This is a National Institute on Deafness and Other Communication Disorders (NIDCD multi-center clinical trial to identify and quantitate the role of pharmacologic interventions of prednisone, methotrexate, and cyclophosphamide in reversing or preventing hearing loss among patients diagnosed with idiopathic progressive bilateral sensorineural hearing loss. Treatment will be assessed by objective criteria defined by performance on standarized audiometric tests throughout the 52 weeks of planned follow-up. Study results will provide information on IPBSNHL